Meanwhile, members of both parties said that the partisan fight over whether to tap Social Security's surpluses for other federal activities seemed finished, at least for now. Though that issue had seemed destined to dominate this fall's political battle, the enormity of Tuesday's destruction in New York and Washington had lawmakers saying they should respond to the incidents, no matter where the money comes from.

''That debate is over at this point,'' said Sen. Richard Durbin, D-Ill. ''I'm not going to bury my head in the sand and say I'm taking that position, regardless of America's security.''

After considering a range from $5 billion to more than $25 billion, administration officials and some top lawmakers decided to seek $20 billion, said one congressional Republican aide speaking on condition of anonymity.

House Appropriations Committee Chairman Bill Young, R-Fla., said the goal was to push the legislation through Congress and to President Bush's desk on Thursday. The Appropriations panel approves federal spending.

''We want a swift, positive reaction from Congress, and appropriating the money is just that,'' Young told reporters.

But Senate Majority Leader Tom Daschle, D-S.D., said he doubted that the measure could be approved in one day and said there was no final agreement on a dollar amount.

''It's premature to be announcing a figure,'' he told reporters.

Lawmakers of both parties balked at an initial White House plan to seek a virtual blank check for taking whatever actions the president considered necessary.

''I didn't come here to have written on my tombstone that any president could, if he wanted, put eight divisions into Afghanistan or go to war with the entire Arab world ... without consulting with any other human being in government,'' said Rep. David Obey of Wisconsin, top Democrat on the House Appropriations Committee.

According to wording that circulated on Capitol Hill, an early version of the administration's bill would have provided ''such sums as may be necessary to respond to the terrorist attacks on the United States.''

After the president met with congressional leaders of both parties, White House spokesman Ari Fleischer said Bush believes the request should not be open-ended.

''We're going to work with Congress on the specifics of it,'' said Fleischer, who added that estimates of a multibillion-dollar price tag were correct.

The measure was expected to provide money for rebuilding the damaged Pentagon, cleaning up the debris of New York's two World Trade Center towers, reimbursing federal and local governments for rescue efforts, and bolstering security.

Senate Minority Leader Trent Lott, R-Miss., suggested several approaches, including providing a specified amount of money and leaving the door open for more funds later.

In addition, many of the 13 regular spending bills for the coming fiscal year also seemed likely to be altered so extra money could be included for defense, intelligence, air system safety and other activities. Congress is in the early stages of its work on those bills, which cover the fiscal year beginning Oct. 1.

''We will work with the administration to allocate the resources and to dedicate whatever strategy may be required to fulfill our obligations,'' Daschle told reporters.

As for the Social Security surplus, signs abounded that members of both parties were setting aside that fight for now. House Budget Committee Chairman Jim Nussle, R-Iowa, indefinitely postponed plans for his committee to write a bill that would automatically cut spending by the amount the Social Security surplus is eroded.

Bush and most members of both parties have long promised to leave the surplus generated by the giant pension program alone, using it only for debt reduction, as a sign of their fiscal austerity.

As the limp economy and the costs of this year's tax cut have squeezed the budget, Democrats and Republicans have warred over how to avoid siphoning Social Security funds to pay for plans to boost defense, schools and other programs.

But in the wake of Tuesday's terror attacks, such talk was on the wane, with many lawmakers and officials emphasizing that their pledge was not meant to apply during war, recession or emergencies.

''I think that this is the definition of a severe emergency,'' Fleischer said of Tuesday's devastation.

''Our clear priority and national need is to defend our country and rebuild,'' said Senate Budget Committee Chairman Kent Conrad, D-N.D., who has often accused Bush's tax cut of draining Social Security funds. ''The integrity of the (Social Security) trust funds is also a critical priority, but the urgent need is to defend our country.''

It was unclear, however, whether the apparent truce over Social Security applied only to anti-terrorism expenditures, or would last for the rest of this fall's budget cycle. Many lawmakers from both sides said it was too early to tell.